First attempt at masking and rattle can spraying

[RichD1]

I've just started to make the Tamiya 1:20 Lotus 25. The main colour bodywork is in several pieces and joins two different colour panels, the chassis and the under tray. 

 

Do I spray the parts before fitting together and try and scrape clean the surfaces which need glueing or attempt a rather tricky masking operation?

 

Richard

[speedy]

Whatever you choose when I use aerosols make sure they're are nicely warm3d and mixed. I stand the cans in a dish of hot water, shake and repeat. It goes down quite nicely and you'll struggle to get orange peel.

[SnøMotion]

Personally, I'd paint them separately. But I avoid masking at all cost, because I hate it.

 

Martin

[Spiny]

I'm afraid I don't think there is a definitive yes/no answer to this. A lot will depend on what the panels are like on the real thing - if they genuinely do present as separate panels on the real car then definitely pain tthem separately. If there are different pieces in the kit which come together to make a single part, it will depend on what sits inside it - if it's something which can fit inside then stick together before painting. But if the bits which you're spraying will need to go around something else and you can't fit it inside you're almost certainly going to want to spray separately again.

 

The best advice I can give at this stage is to start a WIP (work in progress) thread so we can see the parts you're referring to. I know it's a bit daunting, but people on here are genuinely helpful and I know I for one like to see people make progress and improve their skills even more than I do seeing the real experts creating their masterpieces.

[RichD1]

So I'm going to give the 'painting the panels separately' a go. Unfortunately I have to spray in my outside workshop which is currently showing 4C. Going to get all the sprayed bits up together and hopefully the weather temperature has improved by then. What sort of minimum temperature would you recommend spraying at? Could also warm the parts locally and have the spray paint warmed as  @speedy suggested. Not sure about hot water though.

 

Ohh, masking. I've got some Tesa pink decorators low tack tape, would that be ok to use? The edging looks quite fine and does not exhibit the fibrous edges like standard masking tape and it's quite thin.

 

Richard

Edited February 14 by RichD1
Added text.

[SprueMan]

Well, any masking tape is decent enough, I guess.

If you are worried that the tape is too sticky, you can stick it to your skin first then peel it off and apply to the model. Then take it off as soon as you can.

 

Regarding temperature of spray cans, warm water is enough. Just run some good warm water from the tap at home into a small jar and put the spray can in there so it is covered 3/4 of the way for a 15 minutes or so.

If you just go outside, spray one or two passes, then go back inside it will be alright.

 

Just be mindful that the smell will follow  The gases will continue to evaporate for a bit after you sprayed the model.

[Spiny]

8 hours ago, RichD1 said:

So I'm going to give the 'painting the panels separately' a go. Unfortunately I have to spray in my outside workshop which is currently showing 4C. Going to get all the sprayed bits up together and hopefully the weather temperature has improved by then. What sort of minimum temperature would you recommend spraying at? My experience has been that humidity seems to be the key factor - Halfords cans suggest not spraying below 10 degrees but I've got away with that before on cooler dryer days. Conversely, I've sprayed at 13-15 degrees but over 75% Relative Humidity and not really been satisfied with the result. Could also warm the parts locally and have the spray paint warmed as  @speedy suggested. Not sure about hot water though. Just to clarify the point before you put the plastic parts in hot water, it's the spray can which wants to be warmed up, not the plastic.

 

Ohh, masking. I've got some Tesa pink decorators low tack tape, would that be ok to use? The edging looks quite fine and does not exhibit the fibrous edges like standard masking tape and it's quite thin.

 

Richard

 

Couple of little bits in red in the quote. It's not great for painting in winter, although I think the current dry spell is better for it than a bit warmer but always raining. That's why I usually try and get bodyshells painted in summer ready for winter, but I appreciate that you're not in a position to do that at the moment. Is there any heater available to heat up your worktop even a little bit before painting - even adding a couple of degrees could help and that will also aid in reducing the humidity.

[Neddy]

One other thing - if you can, have ready some thing like a Really Useful box you can put over the model immediately after spraying.  It'll help keep the Dreaded Dust Particles off the wet surface.

[SnøMotion]

Not to disagree with anything said above (as it is best practice), but I’ve never had an issue spraying with Tamiya rattle cans. My ‘spray booth’ (or The Dirtbox as it’s known) is in the garage and I spray all year. Sometimes I have popped the can in the kitchen to warm up beforehand, but it doesn’t seem to make a difference.

 

Since getting an airbrush, I’ve experienced the same. A couple of weeks ago, I had trouble cleaning the airbrush because I couldn’t feel the ends of my fingers, but the paint came out fine 

[RichD1]

Almost ready with cleaning up the parts to make a start.

 

Primer first, can I use Halfords grey primer (which I already have) or is this too rough for bodywork finish?

 

Richard

[Pete in Lincs]

Do you plan to wash and or sand the panels before primer? A rub down with micro mesh or really fine wet & dry will help the primer to grip. You then shouldn't get any peeling problems. 

After the primer is dry you can then repeat with a very light sanding to smooth it out. 

I've use a brand  of plastic primer called Hycote for years now and not had problems by doing the above actions. 

Oh, yes, do warm the can & shake it until your arm hurts! Happy spraying.

 

[SnøMotion]

You should be fine with Halfords primer, @RichD1  As @Pete in Lincs says, it’d be worth giving the primer (and the plastic prior to primer) a light rub with some fine abrasive to smooth it a little.

 

I tend to use the Tamiya 3000 grit sponge to prep the plastic and smooth the primer. More experienced people than I might well use a more coarse grit, but I can’t do much damage with 3000! 

Martin

[RichD1]

4 hours ago, Pete in Lincs said:

Do you plan to wash and or sand the panels before primer? A rub down with micro mesh or really fine wet & dry will help the primer to grip. You then shouldn't get any peeling problems. 

After the primer is dry you can then repeat with a very light sanding to smooth it out. 

I've use a brand  of plastic primer called Hycote for years now and not had problems by doing the above actions. 

Oh, yes, do warm the can & shake it until your arm hurts! Happy spraying.

 

 

Yes, I've started cleaning up all the parts which need spraying. Using a craft scalpel knife to remove sprue witness marks and flashing around edges. I've found a light scraping with the scalpel blade was far better than using a needle file and fine abrasive. Then a final rub with a fine scotch pad. Will then degrease with an IPA wipe over.

 

Richard

[Spiny]

Regarding Halfords primer, that's the only primer I've used (white or grey so far, although I've got some red for a build which should get sprayed in summer). For the Lotus colours it probably doesn't matter too much and I'd expect grey to be the right primer for it, but going forward be aware that for some shades the primer can make a BIG difference to the colour, the pic below shows the same orange sprayed over white and grey primer.

 

 

Moral of the photo, check the paint first before choosing your primer. Incidentally, although I used to just leave the Halfords primer as it sprayed I've started giving it a quick and light rub over with 1000grit to get rid of the worst of the texture. No need to go mad though, and you can get away without it.

[Alan R]

I have used both Halford's grey and red primers and Zero Paints Grey primer.

Zero Paints primer seems to be a bit 'finer'. However, I would be careful with both primers. Apply the primer in very light coats as the primer can be a bit 'hot', especially the ZP primer.

Three or more fine coats should probably be enough. Then sand with 1200 grit carefully to remove the inevitable (for me anyway) blemishes. You may have to re-prime small areas as you may burn through the primer. I do anyway!

 

Cheers,

Alan.

[Zephyr]

Maybe a bit late, but assuming your Tesa tape is paper masking tape, I always, no matter how good the edge looks, lay it on a smooth, clean surface and trim the edge with a sharp blade.

If I don't, either the edge of the paper or the adhesive causes an irregular paint line somewhere.